This study, aims to establish an evaluation workflow using geophysical measurements to prevent building hazards due to ground collapse, settling and subsidence in areas with former mining activity. This workflow should be applicable to locations with a similar historical background to the study site to attain public safety, providing an alternative, urban friendly and non-destructive inspection method.
Geophysical measurements are often used to determine the state of the underground and to detect possible structural weaknesses. In contrast to the direct underground investigations, like drilling, the on-surface prospection is less expensive and less destructive. This study is intended to investigate the applicability of geophysical measurements for the determination of the subsurface stability of an old coal mine in the area of GeothermieZentrum of Bochum.
Former studies and reports of the selected area were taken into consideration to approximate the geological and structural condition of the subsurface. These reports incorporate information about the preceding restoration projects that took place along the last 40 years and help us gain a sufficient image about what is to be expected into the subsurface. This information was used in combination with the geophysical data, obtained during the current study, to attain results about the state of the ground and to create general implications for the suitability of geophysical investigations of old near-surface coal mines.
The used geophysical methods are the ground penetrating radar (GPR), geoelectric prospection, and seismic refraction. The collected data were processed and evaluated with several specialized programs, such as, ReflexW, Geotom, Bert, Res2DInv, and FMtomo. The maximum estimated penetration depth through the final inversion process is 30-40 m, depending on the type of the survey.
Table of Contents
Abstract
1. Introduction
1.1 Motivation
1.2 Research Area
1.2.1 Geology
1.2.2 Former Studies
2. Surveys and Theoretical Background
2.1 Ground Penetrating Radar Survey
2.2 Geoelectric Survey
2.3 Seismic Survey
3. Field measurements
3.1 Measurements at the western side of GZB
3.2 Measurements at the eastern side of GZB
4. Data Processing and Results
4.1 Analyses of radargrams with ReflexW
4.2 Inversion of pseudo-sections with BERT and DC2DInvRes
4.2.1 Geoelectric data analysis of the western side of GZB
4.2.2 Geoelectric data analysis of the eastern side of GZB
4.3 Seismogram processing with FMTOMO
4.3.1 Analysis of the pre-existing seismic data near GZB building
4.3.2 Analysis of the seismic data from the survey at the eastern side of GZB
5. Interpretation
5.1 West of GZB
5.2 East of GZB
6. Summary and Conclusions
Acknowledgements
Bibliography
Appendix I
Processing workflow for ground-penetrating radar raw data with ReflexW
Appendix II
Processing geoelectric data with BERT
APPENDIX III
Processing seismic data with ActiveSeismoPick3D
- Quote paper
- Anastasia Kokkinou (Author), 2016, Evaluation of an Old Coal Mine in the area of GeothermieZentrum Bochum by Geophysical Prospection, Munich, GRIN Verlag, https://www.grin.com/document/365484
